Highly available and scalable Cyrus configurations

[Rob Siemborski]

On Tue, 7 Oct 2003, Ben Carter wrote:

> > This is not the case.  Simple DNS round-robining is sufficient.
>
> How is simple DNS round-robin sufficient?  More than one MUA caches the DNS
> lookups for its mail servers.  I know that at least one version of
> Netscape Communicator used to.  It probably still does.  Also, some webmail
> clients do.  So if a front-end is down or has not network connectivity, one
> gets hung MUAs.

Er, I should have said dynamic dns style systems.  Round robin, is, as you
say, not sufficient.

> That's another good point.  However, is this still an issue if one does not
> select the flat file format for the mailboxes file?

Yes.  Concurrent access to the mailbox list is an issue with every
database format.

> Has anyone implemented Cyrus IMAP with any type of clustering softwarethat
> you know of?

I've heard success stories in warm-spare situations where the filesystem
is shared, but only one server is active at a time.

-Rob

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Rob Siemborski * Andrew Systems Group * Cyert Hall 207 * 412-268-7456
Research Systems Programmer * /usr/contributed Gatekeeper